As CO₂ concentrations keep rising and plastic waste continues to overwhelm our oceans, researchers at the University of Copenhagen have unveiled a method that tackles both crises at once – and opens a new feedstock pathway for the Power-to-X value chain.

From Waste to Sorbent: The BAETA Method

The team, led by PhD researcher Margarita Poderyte at the Department of Chemistry, University of Copenhagen, and supported by the Novo Nordisk Foundation CO₂ Research Center (CORC) at Aarhus University, has developed a chemical upcycling process that transforms discarded PET plastic – the material found in bottles, textiles, and packaging – into a highly effective CO₂ capture material they call BAETA. The conversion relies on aminolysis: PET reacts with ethylenediamine at room temperature, producing a powdery solid that binds CO₂ with remarkable capacity (up to 3.4 mol/kg). Crucially, the synthesis works at ambient temperature, requires no exotic reagents, and has already been demonstrated at the 1 kg scale.

Once saturated with CO₂, BAETA can be regenerated by gentle heating – releasing a concentrated stream of CO₂ that can be stored, sequestered, or fed directly into Power-to-X processes such as methanation or e-fuel synthesis. The study was published in Science Advances in September 2025.

Why This Matters for Power-to-X

P2X technologies – whether Power-to-Gas, Power-to-Liquid, or Power-to-Chemicals – all depend on a reliable, affordable supply of CO₂. Today, that CO₂ typically comes from industrial point sources or dedicated direct air capture (DAC) units, both of which carry significant cost and energy burdens. BAETA introduces a third option: a CO₂ sorbent whose feedstock is a waste stream that currently has no viable end-of-life solution.

The material is effective both at high CO₂ concentrations (flue gas: 5–20%) and at ambient air levels (~400 ppm), and it remains stable up to 170°C – making it compatible with the thermal conditions of industrial exhausts. For P2X plant operators, this could mean a lower-cost, more sustainable route to CO₂ supply without competing with mechanical recycling streams.

Honest Caveats

The technology is at an early stage. Scale-up to industrial volumes is the next critical step, and the researchers acknowledge that attracting investment is the decisive challenge – not the chemistry. A full lifecycle assessment comparing BAETA-based CO₂ capture against established alternatives has yet to be published. And while the Power-to-X integration is a compelling vision, it remains a downstream application to be demonstrated, not an operational reality.

SPIN Perspective

At SPIN – Swiss Power-to-X Collaborative Innovation Network, we track the full Power-to-X value chain – from renewable electricity generation through conversion, storage, and utilisation. CO₂ sourcing is one of the less-discussed bottlenecks in scaling up e-fuels and synthetic methane. Research like the Copenhagen team’s work reminds us that the solutions may come from unexpected directions: in this case, the mountains of plastic waste we have been struggling to manage for decades.

We will follow this technology’s development closely. If it scales, it could become a meaningful piece of the P2X puzzle – not a silver bullet, but a genuinely clever way to turn two problems into one solution.

Source: Poderyte et al., Science Advances, September 2025. DOI: 10.1126/sciadv.adv5906